Research advances over the last several years have provided overwhelming evidence that the health of humans, and likely most other animals, is dependent upon their associations with persistent, coevolved communities of microorganisms. Not only do these consortia of beneficial microbes play a critical role in day-to-day physiological homeostasis, but also they partner with the host's immune system to successfully resist pathogenesis. This latter role has taken on an increasing significance in an age of emerging infectious diseases and sophisticated bioweapons development. Investigation of the normal microbiota and its interactions with the host has been enabled by recent technical advances in molecular biology, biotechnology, computational biology, metabolic modeling, and bioinformatics, including the development of metagenomics methods to identify the constituents and potential capabilities of microbial consortia, and genetic and genomic approaches to determine the depth of their influence on host biology. The ASM Beneficial Microbes Conferences, held in 2005, 2008, and now 2010, are internationally attended meetings that bring together biologists in areas ranging from molecular genetics to metagenomics to systems biology and ecology to discuss the development of this frontier field of research. Funding is requested for the support of United States and international scientists attending the upcoming meeting entitled 'Beneficial Microbes Conference 2010 - Host-Microbe Interactions in Health and Disease'sponsored by the American Society for Microbiology (ASM), to be held in Miami, Florida, October 25-29, 2010. The meeting has six sessions devoted to exploring the current state of the field and defining new directions of inquiry. The first session focuses on how beneficial microorganisms play an essential role in programming and directing normal development of the host. We follow with a second set of presentations describing advances in our understanding of the genetic mechanisms underlying host-microbe communication and coordination. The third session highlights a new focus of the Conference: the application of computational approaches to model the ecology and evolution of the complex microbial consortia of animals. Because the immune system is the major element in an animal's response to the presence of microbes, the fourth session is devoted to exploring the role of the microbiota in normal immune function, and the recognition signals that allow communication between a host and its specific symbiotic partners. In the fifth session, we continue our new focus: specifically, the application of metagenomics and mathematical modeling to predict the complex interactions that maintain beneficial associations. The last session looks to the future, and to how beneficial animal-microbe interactions with the host play a vital role at the interface of health and disease. PUBLIC HEALTH RELEVANCE: Recent research has demonstrated that humans require interactions with thousands of coevolved microbial species for health, and that the activity of these microbes is likely to profoundly affect all aspects of human physiology and immunology. The recognition of this phenomenon is revolutionizing the way biologists and biomedical scientists view the form and function of the human body. 'Beneficial Microbes Conference 2010 - Host-Microbe Interactions in Health and Disease'is an American Society for Microbiology-sponsored meeting devoted to exploring this frontier. The aim of this conference is to provide a forum for discussion and exchange of ideas, and for the development of new approaches and a conceptual synthesis.